The phosphotungustic acid catalysed oxidation of aliphatic hydroxy acids by halo -oxidant Nchlorosuccinide (NCS) in aqueous acetic acid lead to the formation of corresponding acetone di-carboxylic acid and acetaldehyde. The reaction follows first to zero order kinetic with respect to [NCS] and rate unchanged by hydrogen ion. The rate of oxidation retards with decrease in dielectric constant of solvent. The study showed curvature due to of complex formation between substrates and postulated species HOCl of oxidant. The stoichiometric ratio 1:1 was determined for the reactions. The correlation between enthalpies and free energies of activation is reasonably linear. A suitable mechanism in conformity with kinetics results was proposed.